Gasoline containing borated oxazolines



United States Patent 9 GASOLINE CONTAINING BQRATED OXAZOLINES Richard J. De Gray, Shaker Heights, and Sarah H. Belden,

Cleveland, Ohio, assignors to The Standard Oil Company, Cleveland, Ohio, a corporation of Ohio No Drawing. Filed Feb. 25, 1959, Ser. No. 795,349 Claims priority, application Great Britain Mar. s, 1958 4 Claims. 01. 44-63) the radical -(CH ),,OH where n is a small whole number such as 1 to 3, and where R represents a radical selected from the group consisting of R hydrogen, or a lower alkyl radical having 1 to 3 carbon atoms.

When R is R,., the compounds will have the formula:

When R is hydrogen or an alkyl radical, the compounds have the formula:

It is well known in the prior art that the continued operation of the internal combustion engine results in the formation of combustion chamber deposits. This deposit problem is particularly aggravated when tetraethyl lead is contained in the fuel for the purpose of increasing the octane number of the fuel to'a desired level for modern high-compression engines. The use of leaded fuels leaves combustion chamber deposits which are no longer essentially carbonaceous in chemical nature, but comprise appreciable quantities of lead compounds generally mixed in the carbonaceous material. The fact that such I deposits are partially metallic in character is believed to give ita catalytic activity which modifies the action of ,the deposit in-aifecting engine operation. De-

spite the fact that one or more volatile organic halides 2,965,459 Patented Dec. 2Q, 1960 such as ethylene dichloride and/or ethylene dibromide are included in the fuel as scavenging agents, not all the lead is removed.

Combustion chamber deposits, and particularly deposits resulting from the burning of leaded fuels, produce a number of adverse effects in engine operation, notable among which is a tendency for these deposits to become heated to incandescence, developing one or more hot spots in the combustion chamber. These spots ignite the fuel either before or after the position in the cycle at which the fuel would normally be ignited by the spark of the sparkplug. This condition, referred to commonly, as surface ignition, manifests itself in various ways characterized as different forms of knocking or engine roughness, and usually resulting in appreciable power loss.

It has already been proposed that the introduction of organo boron compounds into a gasoline serves to alleviate the adverse effects of combustion chamber deposits either by the removal of some of these deposits or by altering such deposits to increase the efl'iciency of combustion in the combustion chamber of the engine. However, many organo boron compounds are not sufficiently stable or adequately soluble and stable in gasoline to be suitable for commercial use. The boron compounds of this invention, in contradistinction to many other classes -of organo boron compounds, are liquids that are highly resistant to crystallization in their pure form even when exposed to very humid atmospheric conditions. Consequently, they may be prepared well in advance of the time when'it is required for them to be incorporated into gasoline and may be blended into gasoline without any specialprecautions to avoid contact with moisture.

Furthermore, these boron compounds, when dissolved in i gasoline, exhibit excellent stability. toward hydrolysis, v. enabling them to be satisfactorily used in large scale manufacturing and marketing operations where the gasoline containing the boron compound must be placed in storage tanks at bulk stations, at filling stations, and him dividual cars, all of which normally contain small It will be obvious that unless the boron compound is hydrolyti amounts of water at the bottom thereof.

cally stable, the contact of the gasoline with such water bottoms will gradually result in the hydrolysis of the boron compound, resulting in the formation of boric acid or other compound forms which precipitate from the hydrocarbon phase to the water phase that is present and the additive is lost for any benefit in the combustion chamber. Solid precipitates forming from such unstable compounds may also clog fuel lines and filters or otherwise interfere with the operation of the engine.

In addition to overcoming in great part the adverse ;;efl:'ects due to combustion chamber deposits, the motor fuels of the present invention are also found particularly helpful in preventing carburetor deposits. Harmful d e; posits commonlyaccumulate in the carburetors of motor vehicles operating in urban areas from contaminated intake air which the carburetor must breathe in in tremendous volumes for engine operation, manifesting themselves by causing rough idling of the engine and in many cases the occurrence of frequent stalling.

Thevmajor contributor to this responsible contamination in the air is believed to be the combustion products exhausted from the large population of other cars operating in the same immediate area. The condition is, of course, aggravated by any blowby fumes from the operation of the cars own engine or by any other under-hood fumes generated by the cars engine, in addition to any industrial fumes present in the air-which the carburetor These sources of contamination are additive in nature and may cause the rapid build-up of deposits breathes.

on the carburetor of the engine.

The motor fuels of the present invention are further characterized by their effectiveness in minimizing carburetor icing. The latter condition represents another troublesome problem attendant" to automotive engines operated in cool, moist,-atmosphericconditions. This when'present in small amounts'in-a motorfuel, are high-' ly effective as anti-rust agents.

The 'above'beneficial effectsare" gained when the boron compounds of thisinv'ention are incorporated-in a gasoline'in amounts between 0.0025 to 0.05 by weight, with amounts from 0.02 to 0.05%by weight'being'preferred.

The substituted oxazoline compound used in preparingthe boron compounds of this invention may be prepared 1 from amino hydroxy' compounds through their fatty amides, or anyother 'known procedure. In preparingthese oxazolines from the fatty acid amides, asuitable amino hydroxy compound is reacted with a de-' sir'able'fatty acid, oramixture thereof, at an elevated temperature to yield the amide. The temperature is then increasedso as to split out water and form the oxazoline.

Any of the compounds having the general formula oflered above are suitable for the invention. The preferred compounds, however, are those in which R as defined heretoforecontains 11 to 17 carbon atoms for maximum solubilityiin hydrocarbon fuel and where R, is the equivalent of R,.

the R; .radical is derived from naturally occurring fats' acidradicalsih'such fats and'oils, such as tallow, cottonseed 'oil, soybeanoil, tall oil, etc. The nature of Re do'es"not'alfect the resultsappreciably, it has been found," andthercforeits selection will be dictatedlargely by economics. The commercial grade of the compounds, including small amounts of impurities of by-products,

reaction may be removed from the reaction mixture as it is formed. This removal of water may be accomplished by simpleboiling, but it is preferable to remove the water by means of azeotropic fractional distillation. Boric oxide may be used inplace of boric acid in these reactions with only the requirement for making the appropriate weightadjustment in order to maintain themolar =relationship with the substituted oxazoline;

The-preparation of these compounds will be better understood in connection with the following example in which "the substituted -oxazoline is 2-heptadecenyl 4,4-

bis-(hydroxy methyl) oxazolinebufwhich istypical of the reaction with other substituted 'oxa'zolines 'of the 'general' fdr-mula previously"desigrlateid; The parts. referred to in the examples are partsby"-"weight"unlessotherwise noted.

Mixtures ofcompcunds' may be used as 'R and this frequently will be the casesince: 40

and 'oils, and hence R will .correspond' to the fatty 4 EXAMPLE 1 parts of Z-heptadecenyl 4,4-bis-(hydroxy methyl) oxazoline was dissolved in 200 parts of benzene. 16.8 parts of boric acid was then added (a 1:1 molar ratio) and the mixture refluxed atthe azeotropic distillation temperature for T the? removal of water with the benzene:-

overhead. from the reaction mixture. The remainder of the'benzene'was distilled "olff The reaction proceeds readily inaccordance' with the followingiequation:

CHaOH rI-o\ H0'\ CnHga-C CHQOH-l- IVB-OH- o-Jm, no

OHg-O (J mmi -G CHr-CY 2HiO O-lH The reactiomproduct was a clear liquid upon cooling' and was soluble in gasoline."

EXAMPLE 2 50 parts of Z-heptadecenyl 4',4-bis-(hyd.roxy methyl) oxazoline was dissolved in 100 parts of benzene. 8.4 parts of dry boric acidwas then added (a 1:1 molar ratio)"and*themixture 'refli1xedfor severalhours at the" azeotropic distillation -temperature'fdr theremoval of water'overhead. The reaction proceeds in accordance with *the following equation:-

CuHu- EXAMPLE 3- 10011 -15 f z-heptadece'nyl 4-methy1', 4'hydroxy' methyl oxazoline was dissolved in 200 parts 'of' benzene. 8.8parts'of boric acid" was then added (a'-2:1 molar ratio) and the' mixtu're was refluxed at the azeotropic' distillationternp'erature" for the removal of water with benzene overhead. The remainder of the benzene was distilled oif. The reaction following equation:

CHs

CnHsr-C C O-CH:

The reaction product was a clear liquid at room temperature and was soluble in gasoline.

The motor fuel consists essentially of one or more hydrocarbon base stocks which may be any of those conventionally used in preparing a motor gasoline for a spark-ignited internal combustion engine, such as cataproceeds according to the lytic distillate, motor polymer, alkylate, catalytic reformate, isomerate, naphthas, etc., and one or more of the above-defined compounds. It is intended that the gasoline of the invention may also contain tetraethyl lead in amounts up to 6 ml., generally up to 3 1111., but at least & ml. per gallon and a scavenging agent. This Surface ignition suppression To determine the eifectiveness of the gasoline of this invention to suppress surface ignition, an AS'IM-CFR single-cylinder engine having the compression ratio adjusted at 12:1 was employed. Preparatory to the test cycle, the engine was run open throttle at 900 rpm. for thirty minutes to stabilize the engine conditions for the test period. Following this, the engine was continued at open throttle. continuously for three hours, during which time the total surface ignition count was observed electronically. All experimental conditions were the same for each test except the gasoline.

The base fuel in each test was the same and had the following composition and specifications:

The number of surface igriitions in the additive fuel is expressed as percentage of the surface ignitions of the blank fuel with the results as follows:

Concentratlon,

SI Rating of Fuel by wt. Total SI Augible None Compound of Example 1.--- Compound of Example 1 Carburetor cleanliness A test was devised to determine an eifective rating for promoting carburetor cleanliness with the gasoline of the invention as compared with the same gasoline not con .taining an oxazoline compound. In this test a contamination system was developed to simulate the conditions which contribute to carburetor deposits in the urban operation of motor vehicles. The system comprises the operation of a slave engine and a test engine. The ex- .haust gases from one bank of the slave engine (four cylinders) is metered to the crankcase of'the test engine at a rate of 1.5 cubic feet per minute.

take of the carburetor of the test engine including, therefore, the exhaust gases from the slave engine and the 'blowby fumes of the test engine. The 1.5 cubic feet per minute rate of exhaust gases from the slave engine under these conditions constitutes approximately 8% of the total air intake of the test engine at idle manifold vacuum and speed. The operating conditions for the two.

eng1nes are as follows:

Test Engine Slave Engine Engines '54 Olds, 10: 1 0.3. '55 Ohrys, l1: 1 GR. Spk. Plugs Champion L12 Champion N-SB. Carburetion Standardgfour-barrel Roeh- Standard tour-barrel ester carburetor. Carter carburetor. Eng. Speed Set up initially for each 700 r.p.m.=l=20.

test at 850 r.p.m. except for accelerations to 3,000 r.p.m., unloadeda Jacket Temp F.:l=5; F.=b5.

The test cycle was 2 hours in time, whichincluded four acceleration periods conducted on the unloaded test engine spaced at /2 hour intervals, the first acceleration .period being 30 minutes after the test cyclewas commenced. During each acceleration period the throttle was moved quickly to a wide open position and then quickly closed again to an idle position five separate times to permit a surge of carburetted gasoline to come into contact with the carburetor parts. The carburetor at the start of each test was in spotless condition. All experimental conditions were the same for the two test cycles except for the 'gasolin'el' The base fuel'in each test was the same and had'the f 'ollowing"compositioii and specifications;

Composition: a

. 'Cat. distillate percent v75 SR naphtha dn -25 API gravity 62.4 -Engler distillation:

IBP F 98 10% F 130 30 F 163 50 F 204 70 F 262 90 F.. 365 EP F.;. 424 Reid vapor pressure 8.75

' At the end .of each test the carburetor was removedv and disassembled and a numerical rating was assigned for-amount of deposits and discoloration by a number of observers rating independently and uninformed of the gasoline they were rating. The rating assigned was based on-a standardized scale ranging from 100 to 0,

All gases from' the crankcase of the test engine are passed to the air in-.

wherein 100 would be a rating of a perfectly clean carburetor. throttleplate and barrel, and rating would represent a throttle plate and barrel loaded with deposits.

Theresults below represent the average rating by the observers;

B P'L nati n, percent bywt.

Additive ta lue- Nona None 60 Componndof Example 1 0. 0025 Compound of Example 1-... 0.02;,

Carburetor. anti-icing A test procedure was. devised simulating the stop-andgo'type of engine operation normally experienced by the motorist during the engine warmup period. The test.

operatedat.2200 rpm. for 15 secondsand .then..de-..

celerated normally to an idle at 450 r.p.m for a maximum of 30 seconds. Performance of the engine was observed during each idle period, and a numerical rating based on the degree of rough idling and engine stalls was assigned so that each fuel received a merit rating on a scale ranging from 100 to 0. By this scheme -an engine operating with a smooth idle overthe idle periods offlevery test cycle would receive a rating of.100, and an engine-which stalled in less than 12 seconds in the idle period of every test cycle would receive a rating of 0.

The basefuel used had the following composition and specifications.

due to their tendency to hydrolyze in the presence of moisture. In this manner, it is posslble to introduce a "desired amount of elemental boron into ai gasoline by utilizing a major an ount of an organo; boron compoundofiering a high elemental boron content but otherwise undesirable due to its hydrolytic stability in conjunction with minor amounts of one or more of the boron compounds of the presentinvention, thereby lowering the total amount of additive required in the fuel and insuring adequate hydrolytic stability. It has been found that the addition of as little as 5 to 10% of the boron addi= tive as a compound of the class set forth 'hereinbefore can significantly improve the hydrolytic stability of various organo boron compounds. This scheme; of introduce.

ing adequate elemental b ron to the combustion chamber to offset. the adverseelfects of combustion-- chamber deposits is particularly fortuitous'since, asewillbe ob; 'vious from the abovereported results, only -veryj'sma1lamounts of the boron compoundseof this inventionare required toprovide significant improvements in engine; operation with respect to carburetor cleaning; and carbu retor anti-icing.-

We claim:

1. A motor fuel for internal combustion enginescon sisting essentially of a leaded gasoline and from 0.002 5, to 0.05% by weight of a boron compound selected from,

thegroup consisting of (1) um-o n-o-x Composition:

Lt. eat. distillate "percent... 48.5 Ultraformate do.. 28.9 Lt. naphtha do 9.7 Isopentane I d 4.9 Butane do 7.8 Solvent oil 7 o 0.2 Tetraethyl lead (motor mix) ml./gal 3.0 API gravity 61.7 Engler distillation:

vapor Pressure. -f The results of this test are as follows:

Concen Additive tration, Rating percent:- by, wt.

z zl l finiund of Example 1 0 02 Compound. of Example 1 0. 0'5 89 As stated heretofore,,the. .boroncompounds of .this nvention are stableztoward hydrolysis-, and particularlyso whenndissolved; in gasoline. It hasybeentound'that smalleamounts ofathese compoundswmay-be added to' gasoline as a 102 3 mpr v g-the. .hydrolytic .staa;

where X' is selected from the group consisting of hydrogen and wherein R represents, an, aliphatic hydrocarbon radical containing 7 to 19 carbon atoms, where n is a small whole number from 1 to 3 and where R represents a radical selected from the group consisting of'hydrogen and-a lower alkyl radical containing 1 to .3 carbon, atoms.

2.- A motor fuel for internal combustion engines consistingessentially-of a leaded-gasoline and from. 0.02 to 0.05%--by weight of'a compound having ay formula:

l Gila-* "whercinR represents an aliphatic hydrocarbon radical containing 7"to. 19 carbon atoms.

3.- A motor. fuel for internal combustionengines consisting essentially of a leadedlgasoline and from 0.02 to 0.05% by weight-ofa compoundhaving aformulazom-o- -o-oH, 2,450,307

RrC l on, me L (3-13: 2:741:548

O- H; H: -O

wherein R represents an aliphatic hydrocarbon radical containing 7 to 19 carbon atoms.

References Cited in the file of this patent UNITED STATES PATENTS Bishop June 1, 1948 McCarthy Oct. 5, 1948 Tryon Apr. 25, 1950 Luvisi Feb. 2, 1954 Darling et a1. Apr. 10, 1956 I UNITED STATES PATENT OFFICE CERTIFICATION OF CORRECTION Patent No. 2,965,459 December 20 1960 Richard Jr De Gray et a1.

rtified that error abears in the above numbered pat- It is hereby ce tion and that the said Letters Patent should read as ent requiring correc corrected below.

' Cblumn 5, lines 10 to 15, the formula should appear as. how?! below instead of as in the patent:

Signed and sealed this 8th day of August 1961.

(SEAL) Attest-z ERNEST W. SWILDER DAVID L. .LADD Attesting Officer Commissioner of Patents UNITED STATES PATENT'OFFICE CERTIFICATION OF CORRECTION Patent No. 2965, 159 December 20, 1960 Richard J. De Gray et al.

that error apea'rs in the above numbered pat- It is hereby certified that the said Letters Patent should read as ent requiring correction and corrected below.

Column 5, lines 10 to 15, the formula should appear as shown below instead of as in the patent:

si n-ed andvsea led this 8th day of'Aug'ust 1961.

(SEAL) Attest-z ERNEST W. SWIDER DAVID L. LADD At-testing Officer Commissioner of Patents. 

1. A MOTOR FUEL FOR INTERNAL COMBUSTION ENGINES CONSISTING ESSENTIALLY OF A LEADED GASOLINE AND FROM 0.002 TO 0.05% BY WEIGHT OF A BORON COMPOUND SELECTED FROM THE GROUP CONSISTING OF (1) 